A game that is played by many Japanese high schoolers. A group of teens, with an equal number of boys and girls, gather at a private place. The boys and girls all pair up and have unprotected sex. After all the boys ejaculate, the couples switch partners. This continues until every boy has had sex with every girl (and visa versa). Now because the girls are at different stages in their cycles, some will not get pregnant (they escaped the bullet as in Russian roulette) and some will get pregnant (they got the bullet as in Russian roulette). But unlike the real Russian roulette, for the girls who got the bullet in this game there is a way out. Because, prior to playing, each player is required to put 5000 yen into a pool called "ejaculation insurance". The collected money is then used to pay for the abortions of any pregnancies that result.

The phenomenon of having to come out as bisexual to the same person/people repeatedly because they assumed or hoped that your sexuality was a "phase." Refers less to the holiday and more to the 1993 Bill Murray comedy film in which the main character experiences the same day over and over.

Like Russian Roulette, but instead of a gun with 1 bullet, you have several potential sexual partners, at least one of whom can give you an STD. Choose wisely.